1 From ef1dbb2df1c0e741486646de40bd638a9c4cd808 Mon Sep 17 00:00:00 2001
2 From: Erik de Castro Lopo <erikd@mega-nerd.com>
3 Date: Fri, 14 Apr 2017 15:19:16 +1000
4 Subject: [PATCH] src/flac.c: Fix a buffer read overflow
5 References: CVE-2017-8362 bsc#1036943
6
7 A file (generated by a fuzzer) which increased the number of channels
8 from one frame to the next could cause a read beyond the end of the
9 buffer provided by libFLAC. Only option is to abort the read.
10
11 Closes: https://github.com/erikd/libsndfile/issues/231
12
13 ---
14 src/flac.c | 11 +++++++++--
15 1 file changed, 9 insertions(+), 2 deletions(-)
16
17 --- a/src/flac.c
18 +++ b/src/flac.c
19 @@ -169,6 +169,14 @@ flac_buffer_copy (SF_PRIVATE *psf)
20 const int32_t* const *buffer = pflac->wbuffer ;
21 unsigned i = 0, j, offset, channels, len ;
22
23 + if (psf->sf.channels != (int) frame->header.channels)
24 + { psf_log_printf (psf, "Error: FLAC frame changed from %d to %d channels\n"
25 + "Nothing to do but to error out.\n" ,
26 + psf->sf.channels, frame->header.channels) ;
27 + psf->error = SFE_FLAC_CHANNEL_COUNT_CHANGED ;
28 + return 0 ;
29 + } ;
30 +
31 /*
32 ** frame->header.blocksize is variable and we're using a constant blocksize
33 ** of FLAC__MAX_BLOCK_SIZE.
34 @@ -202,7 +210,6 @@ flac_buffer_copy (SF_PRIVATE *psf)
35 return 0 ;
36 } ;
37
38 -
39 len = SF_MIN (pflac->len, frame->header.blocksize) ;
40
41 if (pflac->remain % channels != 0)
42 @@ -437,7 +444,7 @@ sf_flac_meta_callback (const FLAC__Strea
43 { case FLAC__METADATA_TYPE_STREAMINFO :
44 if (psf->sf.channels > 0 && psf->sf.channels != (int) metadata->data.stream_info.channels)
45 { psf_log_printf (psf, "Error: FLAC stream changed from %d to %d channels\n"
46 - "Nothing to be but to error out.\n" ,
47 + "Nothing to do but to error out.\n" ,
48 psf->sf.channels, metadata->data.stream_info.channels) ;
49 psf->error = SFE_FLAC_CHANNEL_COUNT_CHANGED ;
50 return ;
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